Hose Run Length for output of Pursan

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Ghost

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Vic, I think I have a problem. Reading the install manual for the pursan/holdntreat I have an issue with the length of the discharge hose. I was wanting to locate the unit in the same place as the old mansfield/tdx system. However, my hose run is about 6 foot as the crow flies, which if I recall properly is the max recommended run of the outlet hose. As the crow flies does not accomodate added length for vented loops and upon closer examination maybe even the outlet location. So...best case scenario I would likely be over the maximum run length by at least two feet.

How much of an issue is this going to be? If I dismount the pursan unit itself, what about the hose run from the holding tank to the Pursan, how long can that be?

Still considering my options, but would appreciate any advice you could give.

Brett
 
Is it a down-hill run? Mine is about 6 feet. The Macerator actually pushes out the treated waste by pushing the holding tanks contents into the Purasan then that it turn pushes the treated waste out if I understand the unit properly. The motors on the PuraSan simply grind the waste and mix it with the Oxydizer.
Bill
 
Somewhat level Bill, but I need to add a vented loop since I will be slightly below water line.
 
Run from holding tank to Purasan should be as short as possible, certainly no more than six feet. The reason being that you don't want raw sewage laying in the hose, where over time it will permeate the hose and stink up the boat. In the case of a Hold N Treat setup, the distance from the tank to the transfer pump, to the Purasan should be as short as you can make it. Ideally, they should be right next to each other.
 
Vic, let me clarify. How big a deal do I have if I'm more than 6 foot from the Pursan to the discharge thru hull? I'm probably 6 foot distance, but obviously that's not the same as 6 foot of hose.
 
The distance from the output of the Purasan to the through-hull isn't of real consequence, as long as the toilet has the ability to pump into the Purasan, through it, then out to the through-hull. Neither the Purasan nor the Lectra/San have a pump inside them. Once put into commisison, the treatment unit never empties. It stays full all the time. The toilet pumps into it, the Purasan grinds everything up and treats it, then holds it. This allows time for exposure of the chemical to the waste inside the unit, for it to be disinfected. Then successive flushes of the toilet push it through and out of the Purasan, by simple displacement. The effluent outputting from the Purasan has been treated, so the distance to the through-hull isn't crucial, as long as the toilet is up to the task of pushing it along.

Where the distance comes into play is the distance between the toilet and the Purasan. A normal 10 second flush of a marine toilet will move the effluent approximately six feet. So the six foot limitation is placed between the toilet and the treatment unit. If the run is more than six feet, the untreated effluent will lay in the lines in-between the two, and eventually the hose will permeate, and the boat will stink.
 
Perfect. Exactly what I was hoping to hear.

In this case this is a vacuflush which over the last 28 years has had no problems pumping into a tank. The location of the tank won't change, only now the tank is being replaced with a Pursan based hold n treat with integrated 15 gallon tank. So I guess there might be an outside chance that the mascerating pump on the hold n treat would not be able to move waste from the tank to the pursan unit (and by extension out through the discharge thru hull), personally looking at the pump I'm game to try it.

The only criticism I would make towards the manual is that it was not clear whether the distance requirement stated from the pursan output to the dischage thru hull was a measurment of distance or hose length. Also I may have misinterpreted the toilet to unit distance requirement as also being the unit to discharge outlet distance.
 
Ghost, the actual hose length is what is used when doing your calculations, not the distance as the crow flies. I'd have thought that was apparent, but maybe not...

Keep in mind that most Raritan manuals in particular, discuss the distance from the toilet to the treatment unit (hose length) when the treatment unit is a stand alone unit.

A Hold N Treat system is a different kettle of fish, as everything goes to the holding tank first, it doesn't go directly from the toilet to the treatment unit.

Also, when connecting to a VacuFlush, the hose length is figured from the output of the vacuum pump, not from the actual toilet. Raritan manuals assume that you're also using a Raritan toilet, but that isn't always the case.
 
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